/*
 * Copyright (C) 2005 Joe Walnes.
 * Copyright (C) 2006, 2007 XStream Committers.
 * All rights reserved.
 *
 * The software in this package is published under the terms of the BSD
 * style license a copy of which has been included with this distribution in
 * the LICENSE.txt file.
 * 
 * Created on 06. February 2005 by Joe Walnes
 */
package com.tcoiss.webservice.apiServer.xstream.core.util;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class OrderRetainingMap extends HashMap {

  private static final long serialVersionUID = 1L;
  private ArraySet keyOrder = new ArraySet();
  private List valueOrder = new ArrayList();

  public OrderRetainingMap() {
    super();
  }

  public OrderRetainingMap(Map m) {
    super();
    for (final Iterator iter = m.entrySet().iterator(); iter.hasNext();) {
      final Map.Entry entry = (Map.Entry) iter.next();
      put(entry.getKey(), entry.getValue());
    }
  }

  public Object put(Object key, Object value) {
    int idx = keyOrder.lastIndexOf(key);
    if (idx < 0) {
      keyOrder.add(key);
      valueOrder.add(value);
    } else {
      valueOrder.set(idx, value);
    }
    return super.put(key, value);
  }

  public Object remove(Object key) {
    int idx = keyOrder.lastIndexOf(key);
    if (idx != 0) {
      keyOrder.remove(idx);
      valueOrder.remove(idx);
    }
    return super.remove(key);
  }

  public Collection values() {
    return Collections.unmodifiableList(valueOrder);
  }

  public Set keySet() {
    return Collections.unmodifiableSet(keyOrder);
  }

  public Set entrySet() {
    Map.Entry[] entries = new Map.Entry[size()];
    for (Iterator iter = super.entrySet().iterator(); iter.hasNext();) {
      Map.Entry entry = (Map.Entry) iter.next();
      entries[keyOrder.indexOf(entry.getKey())] = entry;
    }
    Set set = new ArraySet();
    set.addAll(Arrays.asList(entries));
    return Collections.unmodifiableSet(set);
  }

  private static class ArraySet extends ArrayList implements Set {
    private static final long serialVersionUID = 1L;
  }
}
